Preparation of Microcrystalline Cellulose Directly from Wood under Microwave Radiation

摘要

The influence of the composition of solutions of peracetic acid on a change in the characteristics of cellulose during the oxidative-hydrolytic destruction of aspen and pine wood under microwave radiation was investigated. Samples of the prepared cellulose were characterized by viscometry, X-ray diffraction and IR spectroscopy. It was found that the main factor determining the rate of destruction of cellulose to a low degree of polymerization values in an acid medium at the initial concentration of peracetic acid not exceeding 15% and initial concentration of hydrogen peroxide no more than 3 mol/dm(3) is the concentration of sulfuric acid. The disordering effect of microwave radiation on the crystallites of cellulose during preparation from pine wood in the presence of sulfuric acid in a concentration of 0.06 mol/dm(3) and increased duration of oxidative-hydrolytic treatment from 1 to 2 h was revealed. It was shown that the characteristics of the products obtained from aspen and pine wood by oxidative-hydrolytic treatment with 15% peracetic acid under microwave radiation, the duration of the process of 1.5-2 h and the sulfuric acid concentration of 0.3-0.7 mol/dm(3) correspond to partially oxidized microcrystalline cellulose.